Consider JuiceDefender .

Consider JuiceDefender. This app turns off your data services when the phone's screen is off and then only enables them again for 3 minutes every 15 (this is configurable). By making all your apps sync at once on a schedule you prevent a lot of thrashing on your radios. It can also prevent the wifi from searching for hotspots when you are not close to any stored hotspots. Also, watch out for task killers, since they are always running, monitoring apps, they can end up causing more drain than the apps themselves